Method for crystallizing amorphous layer

Abstract

A method for crystallizing an amorphous layer into a polycrystalline layer. The method uses a substrate under the amorphous layer and a nickel film on the amorphous layer, which are subjected to a heat treatment. The nickel film is formed by a coating step that uses a nickel-containing solution. Alternatively, a nickel and gold, or a nickel and palladium, solution can be used. The method eliminates contamination with metal in the polycrystalline silicon layer and reduces its growth temperature.

What is claimed is:  
     
       1. A method for crystallizing an amorphous layer into a polycrystalline layer, the method comprising the steps of: 
       providing an amorphous layer and a nickel-containing seed film on a substrate structure;  
       said nickel-containing seed film being formed by coating a surface of said amorphous layer or said substrate with a nickel-containing solution, the concentration of nickel in said nickel-containing solution being in the range of between about 10,000 ppm and 100,000 ppm; and  
       heating said amorphous layer and said nickel-containing seed film to convert said amorphous layer into a polycrystalline layer at a lower temperature than if said seed film were not present.  
     
     
       2. The method claimed as in claim  1 , wherein the nickel-containing solution is prepared by dissolving nickel in a solvent. 
     
     
       3. The method claimed as in claim  2 , wherein the solvent is an acid solution. 
     
     
       4. The method claimed as in claims  3 , wherein the acid solution is a nitric acid solution. 
     
     
       5. The method claimed as in claim  3 , wherein the acid solution is a hydrochloric acid solution. 
     
     
       6. The method claimed as in claim  1 , wherein the coating step employs a dipping technique. 
     
     
       7. The method claimed as in claim  1 , wherein the coating step employs a spin coating technique. 
     
     
       8. The method as claimed in claim  1 , wherein the amorphous layer is formed on the substrate and the nickel-containing seed film is formed on the amorphous layer. 
     
     
       9. The method as claimed in claim  1 , where in the nickel-containing seed film is formed on the substrate and the amorphous film is formed on the nickel-containing seed film. 
     
     
       10. The method claimed as in claim  1 , wherein the amorphous layer is an amorphous silicon layer. 
     
     
       11. The method claimed as in claim  10 , wherein the amorphous layer has a thickness in a range of 10 to 100,000 angstroms. 
     
     
       12. The method claimed as in claim  1 , wherein said heating is carried out in a range from 300° to 800° C. 
     
     
       13. The method claimed as in claim  1 , wherein the nickel film is about 0.1 to 100 angstroms thick. 
     
     
       14. The method as claimed in claim  1 , wherein said substrate includes a buffer layer on an insulating substrate. 
     
     
       15. The method as claimed in claim  14 , wherein said substrate includes one of quartz, glass or another oxide. 
     
     
       16. A method for crystallizing an amorphous layer into a polycrystalline layer, the method comprising the steps of: 
       forming an amorphous layer on an insulating substrate structure;  
       forming a nickel-containing seed film by coating said amorphous layer with a nickel-containing solution, said nickel-containing solution having a nickel concentration between about 10,000 ppm and 100,000 ppm; and  
       heating said amorphous layer and said nickel-containing seed film to convert said amorphous layer into a polycrystalline layer at a lower temperature than if said seed film were not present.  
     
     
       17. A method for crystallizing an amorphous layer into a polycrystalline layer, comprising: 
       forming a first amorphous layer on a substrate structure;  
       coating said amorphous layer with a nickel-containing solution to form a seed film;  
       forming a second amorphous layer on said seed film; and  
       heating said first and second amorphous layers and said seed film to convert said first and second amorphous layers into a polycrystalline layer at a lower temperature than if said seed film was not present.